Some Waikato emergency patients are being sent to other hospitals because of a shortage of a specialist type of radiologist in the region.

Interventional radiologists use images like CT scans and X-rays to diagnose or treat certain conditions - for example, guiding equipment internally to stop bleeding.

However, they are so short-staffed at Waikato Hospital that none are able to be on-call on weeknights for emergencies or urgent cases.

Te Whatu Ora/Health NZ director of hospital and specialist services for the region Michelle Sutherland says one of the interventional radiologists has been injured and can't work.

The existing team is unable to "absorb this extra workload", she says.

This means they will only provide after-hours cover over the weekend, because that is when "major trauma events" requiring interventional radiology are more likely to occur, she says.

"If a patient requiring IR is identified during a period without local on-call cover (and they cannot be safely medically managed overnight), they are able to be transported to the nearest alternate hospital, for example the air ambulance would fly to Auckland rather than Hamilton."

RNZ understands Auckland City Hospital has already treated some emergency patients from the region, which also covers Bay of Plenty and Taranaki, and Middlemore would take on some spinal patients because of the shortage.

Despite nationwide restrictions on hiring at Te Whatu Ora, Michelle says Waikato is still actively recruiting for interventional radiologists.

In the meantime, it's seeking locum cover so it can reinstate the 24/7 service, she says.

Because interventional radiology os provided in a limited number of hospitals, it's normal for patients to be transported to access those services, she says.

However, Waikato Hospital is normally one that took patients from nearby regions.

Meanwhile, staffing problems are also continuing at the hospital's intensive care unit.

Months ago it put out a call for specialists to come from other regions to help because it's so short-staffed.

That's still happening as of late June, with doctors from other hospitals still helping to keep it running.

Michelle says there are a number of vacancies for senior intensive care doctors and locums from other Te Whatu Ora hospitals are being used in the meantime.

-RNZ.